A semiconductors structure can be fabricated using a silicon on insulator (SOI) structure. A SOI structure can include a silicon substrate, an insulator and a thin (e.g. less than 100 nm) layer of silicon. A semiconductor structure can include a logic region and an analog region. A logic region can include one or more logic devices and an analog region can include one or more analog devices. In one example, a logic region can include one or more metal-oxide-semiconductor (having any conductor insulator and semiconductor) field effect transistor (MOSFET) and an analog region can include one or more bipolar device. Such MOSFETs can have channels that are defined within the thin silicon layer. A bipolar device can include e.g. an np junction, a pn junction, a bipolar junction transistor (BJT). An electrode of such a bipolar device can be defined within the substrate.